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Helicobacter hepaticus hydrogenase mutants are deficient in hydrogen-supported amino acid uptake and in causing liver lesions in A/J mice.
- Source :
-
Infection and immunity [Infect Immun] 2005 Sep; Vol. 73 (9), pp. 5311-8. - Publication Year :
- 2005
-
Abstract
- Helicobacter hepaticus, a causative agent of chronic hepatitis and hepatocellular carcinoma in mice, expresses a nickel-containing hydrogen-oxidizing hydrogenase enzyme. Growth of a hyaB gene-targeted mutant was unaffected by the presence of hydrogen, unlike the wild-type strain, which showed an enhanced growth rate when supplied with H(2). Hydrogenase activities in H. hepaticus were constitutive and not dependent on the inclusion of H(2) during growth. Addition of nickel during growth significantly stimulated both urease (for wild-type and hyaB) and hydrogenase (for wild-type) activities. In a 5-h period, the extent of (14)C-labeled amino acid uptake by the wild type was markedly enhanced in the presence of hydrogen and was >5-fold greater than that of the hyaB mutant strain. In the presence of H(2), the short-term whole-cell amino acid uptake V(max) of the parent strain was about 2.2-fold greater than for the mutant, but the half-saturation affinity for amino acid transport was the same for the parent and mutant strain. The liver- and cecum-colonizing abilities of the strains was estimated by real-time PCR quantitation of the H. hepaticus-specific cytolethal distending toxin gene and showed similar animal colonization for the hyaB mutant and the wild type. However, at 21 weeks postinoculation, the livers from mice inoculated with wild type exhibited moderate lobular lymphoplasmacytic hepatitis with hepatocytic coagulative necrosis, but the hydrogenase mutants exhibited no histological evidence of lobular inflammation or necrosis.
- Subjects :
- Animals
Biological Transport genetics
Carbon Radioisotopes
Cecum microbiology
Feces microbiology
Helicobacter hepaticus growth & development
Hydrogen metabolism
Hydrogenase metabolism
Immunohistochemistry
Liver Diseases metabolism
Liver Diseases pathology
Male
Mice
Mice, Inbred A
Nickel metabolism
Amino Acids metabolism
Helicobacter Infections metabolism
Helicobacter Infections microbiology
Helicobacter hepaticus enzymology
Helicobacter hepaticus genetics
Hydrogenase genetics
Liver Diseases microbiology
Mutagenesis, Insertional
Subjects
Details
- Language :
- English
- ISSN :
- 0019-9567
- Volume :
- 73
- Issue :
- 9
- Database :
- MEDLINE
- Journal :
- Infection and immunity
- Publication Type :
- Academic Journal
- Accession number :
- 16113246
- Full Text :
- https://doi.org/10.1128/IAI.73.9.5311-5318.2005